The present invention relates to check valves and relates in particular to check valves useful in pipe lines, pumps and process equipment that are inclined to the vertical.
Prior art check valves of the ball and seat type used on inclined pipeline applications tend to respond to gravity causing them to settle to the side of the pipeline producing an unsymmetrical flow pattern around the ball when the valve is open.
When flow is reversed to effect valve closure the ball follows an irregular and erratic path in finding its way to the valve seat.
During this closure procedure numerous collisions occur causing damage to the ball, the valve body and the valve seat resulting in premature failure of the valve assembly.
In addition, the erratic travel path of the ball during the valve closure operation increases the time to close the valve.